/tmp/bitcoin/src/util/sock.cpp

Source
// Copyright (c) 2020-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <util/sock.h>

#include <compat/compat.h>
#include <span.h>
#include <tinyformat.h>
#include <util/check.h>
#include <util/log.h>
#include <util/syserror.h>
#include <util/threadinterrupt.h>
#include <util/time.h>

#include <algorithm>
#include <compare>
#include <exception>
#include <memory>
#include <stdexcept>
#include <string>
#include <utility>
#include <vector>

#ifdef USE_POLL
#include <poll.h>
#endif

static inline bool IOErrorIsPermanent(int err)
{
    return err != WSAEAGAIN && err != WSAEINTR && err != WSAEWOULDBLOCK && err != WSAEINPROGRESS;
}

Sock::Sock(SOCKET s) : m_socket(s) {}

Sock::Sock(Sock&& other)
{
    m_socket = other.m_socket;
    other.m_socket = INVALID_SOCKET;
}

Sock::~Sock() { Close(); }

Sock& Sock::operator=(Sock&& other)
{
    Close();
    m_socket = other.m_socket;
    other.m_socket = INVALID_SOCKET;
    return *this;
}

ssize_t Sock::Send(const void* data, size_t len, int flags) const
{
    return send(m_socket, static_cast<const char*>(data), len, flags);
}

ssize_t Sock::Recv(void* buf, size_t len, int flags) const
{
    return recv(m_socket, static_cast<char*>(buf), len, flags);
}

int Sock::Connect(const sockaddr* addr, socklen_t addr_len) const
{
    return connect(m_socket, addr, addr_len);
}

int Sock::Bind(const sockaddr* addr, socklen_t addr_len) const
{
    return bind(m_socket, addr, addr_len);
}

int Sock::Listen(int backlog) const
{
    return listen(m_socket, backlog);
}

std::unique_ptr<Sock> Sock::Accept(sockaddr* addr, socklen_t* addr_len) const
{
#ifdef WIN32
    static constexpr auto ERR = INVALID_SOCKET;
#else
    static constexpr auto ERR = SOCKET_ERROR;
#endif

    std::unique_ptr<Sock> sock;

    const auto socket = accept(m_socket, addr, addr_len);
    if (socket != ERR) {
        try {
            sock = std::make_unique<Sock>(socket);
        } catch (const std::exception&) {
#ifdef WIN32
            closesocket(socket);
#else
            close(socket);
#endif
        }
    }

    return sock;
}

int Sock::GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const
{
    return getsockopt(m_socket, level, opt_name, static_cast<char*>(opt_val), opt_len);
}

int Sock::SetSockOpt(int level, int opt_name, const void* opt_val, socklen_t opt_len) const
{
    return setsockopt(m_socket, level, opt_name, static_cast<const char*>(opt_val), opt_len);
}

int Sock::GetSockName(sockaddr* name, socklen_t* name_len) const
{
    return getsockname(m_socket, name, name_len);
}

bool Sock::SetNonBlocking() const
{
#ifdef WIN32
    u_long on{1};
    if (ioctlsocket(m_socket, FIONBIO, &on) == SOCKET_ERROR) {
        return false;
    }
#else
    const int flags{fcntl(m_socket, F_GETFL, 0)};
    if (flags == SOCKET_ERROR) {
        return false;
    }
    if (fcntl(m_socket, F_SETFL, flags | O_NONBLOCK) == SOCKET_ERROR) {
        return false;
    }
#endif
    return true;
}

bool Sock::IsSelectable() const
{
#if defined(USE_POLL) || defined(WIN32)
    return true;
#else
    return m_socket < FD_SETSIZE;
#endif
}

bool Sock::Wait(std::chrono::milliseconds timeout, Event requested, Event* occurred) const
{
    // We need a `shared_ptr` holding `this` for `WaitMany()`, but don't want
    // `this` to be destroyed when the `shared_ptr` goes out of scope at the
    // end of this function.
    // Create it with an aliasing shared_ptr that points to `this` without
    // owning it.
    std::shared_ptr<const Sock> shared{std::shared_ptr<const Sock>{}, this};

    EventsPerSock events_per_sock{std::make_pair(shared, Events{requested})};

    if (!WaitMany(timeout, events_per_sock)) {
        return false;
    }

    if (occurred != nullptr) {
        *occurred = events_per_sock.begin()->second.occurred;
    }

    return true;
}

bool Sock::WaitMany(std::chrono::milliseconds timeout, EventsPerSock& events_per_sock) const
{
#ifdef USE_POLL
    std::vector<pollfd> pfds;
    for (const auto& [sock, events] : events_per_sock) {
        pfds.emplace_back();
        auto& pfd = pfds.back();
        pfd.fd = sock->m_socket;
        if (events.requested & RECV) {
            pfd.events |= POLLIN;
        }
        if (events.requested & SEND) {
            pfd.events |= POLLOUT;
        }
    }

    if (poll(pfds.data(), pfds.size(), count_milliseconds(timeout)) == SOCKET_ERROR) {
        return false;
    }

    assert(pfds.size() == events_per_sock.size());
    size_t i{0};
    for (auto& [sock, events] : events_per_sock) {
        assert(sock->m_socket == static_cast<SOCKET>(pfds[i].fd));
        events.occurred = 0;
        if (pfds[i].revents & POLLIN) {
            events.occurred |= RECV;
        }
        if (pfds[i].revents & POLLOUT) {
            events.occurred |= SEND;
        }
        if (pfds[i].revents & (POLLERR | POLLHUP)) {
            events.occurred |= ERR;
        }
        ++i;
    }

    return true;
#else
    fd_set recv;
    fd_set send;
    fd_set err;
    FD_ZERO(&recv);
    FD_ZERO(&send);
    FD_ZERO(&err);
    SOCKET socket_max{0};

    for (const auto& [sock, events] : events_per_sock) {
        if (!sock->IsSelectable()) {
            return false;
        }
        const auto& s = sock->m_socket;
        if (events.requested & RECV) {
            FD_SET(s, &recv);
        }
        if (events.requested & SEND) {
            FD_SET(s, &send);
        }
        FD_SET(s, &err);
        socket_max = std::max(socket_max, s);
    }

    timeval tv = MillisToTimeval(timeout);

    if (select(socket_max + 1, &recv, &send, &err, &tv) == SOCKET_ERROR) {
        return false;
    }

    for (auto& [sock, events] : events_per_sock) {
        const auto& s = sock->m_socket;
        events.occurred = 0;
        if (FD_ISSET(s, &recv)) {
            events.occurred |= RECV;
        }
        if (FD_ISSET(s, &send)) {
            events.occurred |= SEND;
        }
        if (FD_ISSET(s, &err)) {
            events.occurred |= ERR;
        }
    }

    return true;
#endif /* USE_POLL */
}

void Sock::SendComplete(std::span<const unsigned char> data,
                        std::chrono::milliseconds timeout,
                        CThreadInterrupt& interrupt) const
{
    const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
    size_t sent{0};

    for (;;) {
        const ssize_t ret{Send(data.data() + sent, data.size() - sent, MSG_NOSIGNAL)};

        if (ret > 0) {
            sent += static_cast<size_t>(ret);
            if (sent == data.size()) {
                break;
            }
        } else {
            const int err{WSAGetLastError()};
            if (IOErrorIsPermanent(err)) {
                throw std::runtime_error(strprintf("send(): %s", NetworkErrorString(err)));
            }
        }

        const auto now = GetTime<std::chrono::milliseconds>();

        if (now >= deadline) {
            throw std::runtime_error(strprintf(
                "Send timeout (sent only %u of %u bytes before that)", sent, data.size()));
        }

        if (interrupt) {
            throw std::runtime_error(strprintf(
                "Send interrupted (sent only %u of %u bytes before that)", sent, data.size()));
        }

        // Wait for a short while (or the socket to become ready for sending) before retrying
        // if nothing was sent.
        const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
        (void)Wait(wait_time, SEND);
    }
}

void Sock::SendComplete(std::span<const char> data,
                        std::chrono::milliseconds timeout,
                        CThreadInterrupt& interrupt) const
{
    SendComplete(MakeUCharSpan(data), timeout, interrupt);
}

std::string Sock::RecvUntilTerminator(uint8_t terminator,
                                      std::chrono::milliseconds timeout,
                                      CThreadInterrupt& interrupt,
                                      size_t max_data) const
{
    const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
    std::string data;
    bool terminator_found{false};

    // We must not consume any bytes past the terminator from the socket.
    // One option is to read one byte at a time and check if we have read a terminator.
    // However that is very slow. Instead, we peek at what is in the socket and only read
    // as many bytes as possible without crossing the terminator.
    // Reading 64 MiB of random data with 262526 terminator chars takes 37 seconds to read
    // one byte at a time VS 0.71 seconds with the "peek" solution below. Reading one byte
    // at a time is about 50 times slower.

    for (;;) {
        if (data.size() >= max_data) {
            throw std::runtime_error(
                strprintf("Received too many bytes without a terminator (%u)", data.size()));
        }

        char buf[512];

        const ssize_t peek_ret{Recv(buf, std::min(sizeof(buf), max_data - data.size()), MSG_PEEK)};

        switch (peek_ret) {
        case -1: {
            const int err{WSAGetLastError()};
            if (IOErrorIsPermanent(err)) {
                throw std::runtime_error(strprintf("recv(): %s", NetworkErrorString(err)));
            }
            break;
        }
        case 0:
            throw std::runtime_error("Connection unexpectedly closed by peer");
        default:
            auto end = buf + peek_ret;
            auto terminator_pos = std::find(buf, end, terminator);
            terminator_found = terminator_pos != end;

            const size_t try_len{terminator_found ? terminator_pos - buf + 1 :
                                                    static_cast<size_t>(peek_ret)};

            const ssize_t read_ret{Recv(buf, try_len, 0)};

            if (read_ret < 0 || static_cast<size_t>(read_ret) != try_len) {
                throw std::runtime_error(
                    strprintf("recv() returned %u bytes on attempt to read %u bytes but previous "
                              "peek claimed %u bytes are available",
                              read_ret, try_len, peek_ret));
            }

            // Don't include the terminator in the output.
            const size_t append_len{terminator_found ? try_len - 1 : try_len};

            data.append(buf, buf + append_len);

            if (terminator_found) {
                return data;
            }
        }

        const auto now = GetTime<std::chrono::milliseconds>();

        if (now >= deadline) {
            throw std::runtime_error(strprintf(
                "Receive timeout (received %u bytes without terminator before that)", data.size()));
        }

        if (interrupt) {
            throw std::runtime_error(strprintf(
                "Receive interrupted (received %u bytes without terminator before that)",
                data.size()));
        }

        // Wait for a short while (or the socket to become ready for reading) before retrying.
        const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
        (void)Wait(wait_time, RECV);
    }
}

bool Sock::IsConnected(std::string& errmsg) const
{
    if (m_socket == INVALID_SOCKET) {
        errmsg = "not connected";
        return false;
    }

    char c;
    switch (Recv(&c, sizeof(c), MSG_PEEK)) {
    case -1: {
        const int err = WSAGetLastError();
        if (IOErrorIsPermanent(err)) {
            errmsg = NetworkErrorString(err);
            return false;
        }
        return true;
    }
    case 0:
        errmsg = "closed";
        return false;
    default:
        return true;
    }
}

void Sock::Close()
{
    if (m_socket == INVALID_SOCKET) {
        return;
    }
#ifdef WIN32
    int ret = closesocket(m_socket);
#else
    int ret = close(m_socket);
#endif
    if (ret) {
        LogWarning("Error closing socket %d: %s", m_socket, NetworkErrorString(WSAGetLastError()));
    }
    m_socket = INVALID_SOCKET;
}

bool Sock::operator==(SOCKET s) const
{
    return m_socket == s;
};

std::string NetworkErrorString(int err)
{
#if defined(WIN32)
    return Win32ErrorString(err);
#else
    // On BSD sockets implementations, NetworkErrorString is the same as SysErrorString.
    return SysErrorString(err);
#endif
}

Coverage Report

Created: 2026-04-29 19:21

Line	Count	Source
1		// Copyright (c) 2020-present The Bitcoin Core developers
2		// Distributed under the MIT software license, see the accompanying
3		// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5		#include <util/sock.h>
6
7		#include <compat/compat.h>
8		#include <span.h>
9		#include <tinyformat.h>
10		#include <util/check.h>
11		#include <util/log.h>
12		#include <util/syserror.h>
13		#include <util/threadinterrupt.h>
14		#include <util/time.h>
15
16		#include <algorithm>
17		#include <compare>
18		#include <exception>
19		#include <memory>
20		#include <stdexcept>
21		#include <string>
22		#include <utility>
23		#include <vector>
24
25		#ifdef USE_POLL
26		#include <poll.h>
27		#endif
28
29		static inline bool IOErrorIsPermanent(int err)
30	21	{
31	21	return err != WSAEAGAIN && err != WSAEINTR && err != WSAEWOULDBLOCK && err != WSAEINPROGRESS;
32	21	}
33
34	2.66k	Sock::Sock(SOCKET s) : m_socket(s) {}
35
36		Sock::Sock(Sock&& other)
37	3	{
38	3	m_socket = other.m_socket;
39	3	other.m_socket = INVALID_SOCKET;
40	3	}
41
42	2.66k	Sock::~Sock() { Close(); }
43
44		Sock& Sock::operator=(Sock&& other)
45	4	{
46	4	Close();
47	4	m_socket = other.m_socket;
48	4	other.m_socket = INVALID_SOCKET;
49	4	return *this;
50	4	}
51
52		ssize_t Sock::Send(const void* data, size_t len, int flags) const
53	324k	{
54	324k	return send(m_socket, static_cast<const char*>(data), len, flags);
55	324k	}
56
57		ssize_t Sock::Recv(void* buf, size_t len, int flags) const
58	160k	{
59	160k	return recv(m_socket, static_cast<char*>(buf), len, flags);
60	160k	}
61
62		int Sock::Connect(const sockaddr* addr, socklen_t addr_len) const
63	631	{
64	631	return connect(m_socket, addr, addr_len);
65	631	}
66
67		int Sock::Bind(const sockaddr* addr, socklen_t addr_len) const
68	988	{
69	988	return bind(m_socket, addr, addr_len);
70	988	}
71
72		int Sock::Listen(int backlog) const
73	987	{
74	987	return listen(m_socket, backlog);
75	987	}
76
77		std::unique_ptr<Sock> Sock::Accept(sockaddr* addr, socklen_t* addr_len) const
78	1.01k	{
79		#ifdef WIN32
80		static constexpr auto ERR = INVALID_SOCKET;
81		#else
82	1.01k	static constexpr auto ERR = SOCKET_ERROR;
83	1.01k	#endif
84
85	1.01k	std::unique_ptr<Sock> sock;
86
87	1.01k	const auto socket = accept(m_socket, addr, addr_len);
88	1.01k	if (socket != ERR) {
89	1.01k	try {
90	1.01k	sock = std::make_unique<Sock>(socket);
91	1.01k	} catch (const std::exception&) {
92		#ifdef WIN32
93		closesocket(socket);
94		#else
95	0	close(socket);
96	0	#endif
97	0	}
98	1.01k	}
99
100	1.01k	return sock;
101	1.01k	}
102
103		int Sock::GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const
104	623	{
105	623	return getsockopt(m_socket, level, opt_name, static_cast<char*>(opt_val), opt_len);
106	623	}
107
108		int Sock::SetSockOpt(int level, int opt_name, const void* opt_val, socklen_t opt_len) const
109	3.60k	{
110	3.60k	return setsockopt(m_socket, level, opt_name, static_cast<const char*>(opt_val), opt_len);
111	3.60k	}
112
113		int Sock::GetSockName(sockaddr* name, socklen_t* name_len) const
114	1.60k	{
115	1.60k	return getsockname(m_socket, name, name_len);
116	1.60k	}
117
118		bool Sock::SetNonBlocking() const
119	1.61k	{
120		#ifdef WIN32
121		u_long on{1};
122		if (ioctlsocket(m_socket, FIONBIO, &on) == SOCKET_ERROR) {
123		return false;
124		}
125		#else
126	1.61k	const int flags{fcntl(m_socket, F_GETFL, 0)};
127	1.61k	if (flags == SOCKET_ERROR) {
128	0	return false;
129	0	}
130	1.61k	if (fcntl(m_socket, F_SETFL, flags \| O_NONBLOCK) == SOCKET_ERROR) {
131	0	return false;
132	0	}
133	1.61k	#endif
134	1.61k	return true;
135	1.61k	}
136
137		bool Sock::IsSelectable() const
138	2.62k	{
139	2.62k	#if defined(USE_POLL) \|\| defined(WIN32)
140	2.62k	return true;
141		#else
142		return m_socket < FD_SETSIZE;
143		#endif
144	2.62k	}
145
146		bool Sock::Wait(std::chrono::milliseconds timeout, Event requested, Event* occurred) const
147	852	{
148		// We need a `shared_ptr` holding `this` for `WaitMany()`, but don't want
149		// `this` to be destroyed when the `shared_ptr` goes out of scope at the
150		// end of this function.
151		// Create it with an aliasing shared_ptr that points to `this` without
152		// owning it.
153	852	std::shared_ptr<const Sock> shared{std::shared_ptr<const Sock>{}, this};
154
155	852	EventsPerSock events_per_sock{std::make_pair(shared, Events{requested})};
156
157	852	if (!WaitMany(timeout, events_per_sock)) {
158	0	return false;
159	0	}
160
161	852	if (occurred != nullptr) {
162	730	*occurred = events_per_sock.begin()->second.occurred;
163	730	}
164
165	852	return true;
166	852	}
167
168		bool Sock::WaitMany(std::chrono::milliseconds timeout, EventsPerSock& events_per_sock) const
169	315k	{
170	315k	#ifdef USE_POLL
171	315k	std::vector<pollfd> pfds;
172	815k	for (const auto& [sock, events] : events_per_sock) {
173	815k	pfds.emplace_back();
174	815k	auto& pfd = pfds.back();
175	815k	pfd.fd = sock->m_socket;
176	815k	if (events.requested & RECV) {
177	815k	pfd.events \|= POLLIN;
178	815k	}
179	815k	if (events.requested & SEND) {
180	889	pfd.events \|= POLLOUT;
181	889	}
182	815k	}
183
184	315k	if (poll(pfds.data(), pfds.size(), count_milliseconds(timeout)) == SOCKET_ERROR) {
185	0	return false;
186	0	}
187
188	315k	assert(pfds.size() == events_per_sock.size());
189	315k	size_t i{0};
190	815k	for (auto& [sock, events] : events_per_sock) {
191	815k	assert(sock->m_socket == static_cast<SOCKET>(pfds[i].fd));
192	815k	events.occurred = 0;
193	815k	if (pfds[i].revents & POLLIN) {
194	160k	events.occurred \|= RECV;
195	160k	}
196	815k	if (pfds[i].revents & POLLOUT) {
197	881	events.occurred \|= SEND;
198	881	}
199	815k	if (pfds[i].revents & (POLLERR \| POLLHUP)) {
200	47	events.occurred \|= ERR;
201	47	}
202	815k	++i;
203	815k	}
204
205	315k	return true;
206		#else
207		fd_set recv;
208		fd_set send;
209		fd_set err;
210		FD_ZERO(&recv);
211		FD_ZERO(&send);
212		FD_ZERO(&err);
213		SOCKET socket_max{0};
214
215		for (const auto& [sock, events] : events_per_sock) {
216		if (!sock->IsSelectable()) {
217		return false;
218		}
219		const auto& s = sock->m_socket;
220		if (events.requested & RECV) {
221		FD_SET(s, &recv);
222		}
223		if (events.requested & SEND) {
224		FD_SET(s, &send);
225		}
226		FD_SET(s, &err);
227		socket_max = std::max(socket_max, s);
228		}
229
230		timeval tv = MillisToTimeval(timeout);
231
232		if (select(socket_max + 1, &recv, &send, &err, &tv) == SOCKET_ERROR) {
233		return false;
234		}
235
236		for (auto& [sock, events] : events_per_sock) {
237		const auto& s = sock->m_socket;
238		events.occurred = 0;
239		if (FD_ISSET(s, &recv)) {
240		events.occurred \|= RECV;
241		}
242		if (FD_ISSET(s, &send)) {
243		events.occurred \|= SEND;
244		}
245		if (FD_ISSET(s, &err)) {
246		events.occurred \|= ERR;
247		}
248		}
249
250		return true;
251		#endif /* USE_POLL */
252	315k	}
253
254		void Sock::SendComplete(std::span<const unsigned char> data,
255		std::chrono::milliseconds timeout,
256		CThreadInterrupt& interrupt) const
257	169	{
258	169	const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
259	169	size_t sent{0};
260
261	169	for (;;) {
262	169	const ssize_t ret{Send(data.data() + sent, data.size() - sent, MSG_NOSIGNAL)};
263
264	169	if (ret > 0) {
265	169	sent += static_cast<size_t>(ret);
266	169	if (sent == data.size()) {
267	169	break;
268	169	}
269	169	} else {
270	0	const int err{WSAGetLastError()};
271	0	if (IOErrorIsPermanent(err)) {
272	0	throw std::runtime_error(strprintf("send(): %s", NetworkErrorString(err)));
273	0	}
274	0	}
275
276	0	const auto now = GetTime<std::chrono::milliseconds>();
277
278	0	if (now >= deadline) {
279	0	throw std::runtime_error(strprintf(
280	0	"Send timeout (sent only %u of %u bytes before that)", sent, data.size()));
281	0	}
282
283	0	if (interrupt) {
284	0	throw std::runtime_error(strprintf(
285	0	"Send interrupted (sent only %u of %u bytes before that)", sent, data.size()));
286	0	}
287
288		// Wait for a short while (or the socket to become ready for sending) before retrying
289		// if nothing was sent.
290	0	const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
291	0	(void)Wait(wait_time, SEND);
292	0	}
293	169	}
294
295		void Sock::SendComplete(std::span<const char> data,
296		std::chrono::milliseconds timeout,
297		CThreadInterrupt& interrupt) const
298	49	{
299	49	SendComplete(MakeUCharSpan(data), timeout, interrupt);
300	49	}
301
302		std::string Sock::RecvUntilTerminator(uint8_t terminator,
303		std::chrono::milliseconds timeout,
304		CThreadInterrupt& interrupt,
305		size_t max_data) const
306	38	{
307	38	const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
308	38	std::string data;
309	38	bool terminator_found{false};
310
311		// We must not consume any bytes past the terminator from the socket.
312		// One option is to read one byte at a time and check if we have read a terminator.
313		// However that is very slow. Instead, we peek at what is in the socket and only read
314		// as many bytes as possible without crossing the terminator.
315		// Reading 64 MiB of random data with 262526 terminator chars takes 37 seconds to read
316		// one byte at a time VS 0.71 seconds with the "peek" solution below. Reading one byte
317		// at a time is about 50 times slower.
318
319	169	for (;;) {
320	169	if (data.size() >= max_data) {
321	2	throw std::runtime_error(
322	2	strprintf("Received too many bytes without a terminator (%u)", data.size()));
323	2	}
324
325	167	char buf[512];
326
327	167	const ssize_t peek_ret{Recv(buf, std::min(sizeof(buf), max_data - data.size()), MSG_PEEK)};
328
329	167	switch (peek_ret) {
330	0	case -1: {
331	0	const int err{WSAGetLastError()};
332	0	if (IOErrorIsPermanent(err)) {
333	0	throw std::runtime_error(strprintf("recv(): %s", NetworkErrorString(err)));
334	0	}
335	0	break;
336	0	}
337	0	case 0:
338	0	throw std::runtime_error("Connection unexpectedly closed by peer");
339	167	default:
340	167	auto end = buf + peek_ret;
341	167	auto terminator_pos = std::find(buf, end, terminator);
342	167	terminator_found = terminator_pos != end;
343
344	167	const size_t try_len{terminator_found ? terminator_pos - buf + 1 :
345	167	static_cast<size_t>(peek_ret)};
346
347	167	const ssize_t read_ret{Recv(buf, try_len, 0)};
348
349	167	if (read_ret < 0 \|\| static_cast<size_t>(read_ret) != try_len) {
350	0	throw std::runtime_error(
351	0	strprintf("recv() returned %u bytes on attempt to read %u bytes but previous "
352	0	"peek claimed %u bytes are available",
353	0	read_ret, try_len, peek_ret));
354	0	}
355
356		// Don't include the terminator in the output.
357	167	const size_t append_len{terminator_found ? try_len - 1 : try_len};
358
359	167	data.append(buf, buf + append_len);
360
361	167	if (terminator_found) {
362	36	return data;
363	36	}
364	167	}
365
366	131	const auto now = GetTime<std::chrono::milliseconds>();
367
368	131	if (now >= deadline) {
369	0	throw std::runtime_error(strprintf(
370	0	"Receive timeout (received %u bytes without terminator before that)", data.size()));
371	0	}
372
373	131	if (interrupt) {
374	0	throw std::runtime_error(strprintf(
375	0	"Receive interrupted (received %u bytes without terminator before that)",
376	0	data.size()));
377	0	}
378
379		// Wait for a short while (or the socket to become ready for reading) before retrying.
380	131	const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
381	131	(void)Wait(wait_time, RECV);
382	131	}
383	38	}
384
385		bool Sock::IsConnected(std::string& errmsg) const
386	105	{
387	105	if (m_socket == INVALID_SOCKET) {
388	0	errmsg = "not connected";
389	0	return false;
390	0	}
391
392	105	char c;
393	105	switch (Recv(&c, sizeof(c), MSG_PEEK)) {
394	21	case -1: {
395	21	const int err = WSAGetLastError();
396	21	if (IOErrorIsPermanent(err)) {
397	0	errmsg = NetworkErrorString(err);
398	0	return false;
399	0	}
400	21	return true;
401	21	}
402	0	case 0:
403	0	errmsg = "closed";
404	0	return false;
405	84	default:
406	84	return true;
407	105	}
408	105	}
409
410		void Sock::Close()
411	2.67k	{
412	2.67k	if (m_socket == INVALID_SOCKET) {
413	34	return;
414	34	}
415		#ifdef WIN32
416		int ret = closesocket(m_socket);
417		#else
418	2.63k	int ret = close(m_socket);
419	2.63k	#endif
420	2.63k	if (ret) {
421	0	LogWarning("Error closing socket %d: %s", m_socket, NetworkErrorString(WSAGetLastError()));
422	0	}
423	2.63k	m_socket = INVALID_SOCKET;
424	2.63k	}
425
426		bool Sock::operator==(SOCKET s) const
427	4	{
428	4	return m_socket == s;
429	4	};
430
431		std::string NetworkErrorString(int err)
432	38	{
433		#if defined(WIN32)
434		return Win32ErrorString(err);
435		#else
436		// On BSD sockets implementations, NetworkErrorString is the same as SysErrorString.
437	38	return SysErrorString(err);
438	38	#endif
439	38	}